Film inspection method

Abstract

In the polishing apparatus and film inspection method, a polishing apparatus for polishing an object causes a relative movement between a polishing body and the polishing object. A polishing agent is then interposed between the polishing body and the polishing object. The polishing apparatus includes an optical measuring system capable of measuring at least one of a polished surface state of the polishing object or a film thickness of the polishing object and a position detection system capable of detecting relative positions of the optical measuring system and the polishing object. A control system is also included, and is capable of controlling at least one of the optical measuring system or the polishing object in accordance with position detection system signals so that prescribed endpoint detection regions of the polishing object are measured by the optical measuring system. A film thickness inspection method optically detects the film thickness of the outermost layer on a semiconductor substrate on which desired wiring patterns are formed in predetermined chip regions by laminating a plurality of layers. The film thickness inspection method includes selecting regions other than the chip regions on the semiconductor substrate, and the film thickness is optically detected by illuminating these regions with light.

What is claimed is: 
     
       1. A film thickness inspection method that optically detects a film thickness of an outermost layer of a semiconductor substrate, the semiconductor substrate having chip regions and non-chip regions such that wiring patterns are formed on the chip regions and not on the non-chip regions, the film thickness inspection method comprising the steps of: selecting non-chip regions on the semiconductor substrate; and   optically detecting the film thickness of the outermost layer of the semiconductor substrate by illuminating the non-chip regions with light.   
     
     
       2. A film thickness inspection method comprising the steps of: polishing an outermost layer of a semiconductor substrate, the semiconductor substrate including wiring patterns formed thereon in predetermined chip regions;   contacting the outermost layer of the semiconductor substrate to a base plate and rotating the base plate;   illuminating the outermost layer of the semiconductor substrate with light through a window formed in a surface of the base plate while the polishing is being performed;   detecting reflected light from the semiconductor substrate;   selecting a detection signal produced from the reflected light when a non-chip region of the semiconductor substrate passes over the window formed in the base plate; and   determining a film thickness of the outermost layer of the semiconductor substrate from the selected detection signal.   
     
     
       3. The film thickness inspection method according to claim 2, wherein the base plate is stopped and polishing is completed when the determined thickness of the outermost layer of the semiconductor substrate reaches a predetermined film thickness. 
     
     
       4. The film thickness inspection method according to claim 2, wherein the detection signal produced when the non-chip region passes over the window is selected by selecting a detection signal region in which an output level of the detection signal is flat. 
     
     
       5. The film thickness inspection method according to claim 2, wherein the detection signal produced when the non-chip region passes over the window is selected by selecting the detection signal that is produced when a peripheral portion of the semiconductor substrate passes over the window. 
     
     
       6. A film thickness inspection method comprising the steps of: polishing an outermost layer on a semiconductor substrate, wherein the semiconductor substrate includes wiring patterns formed in predetermined chip regions and wherein polishing is accomplished by causing the outermost layer of the semiconductor substrate to contact a rotating base plate;   illuminating the outermost layer of the semiconductor substrate during polishing when non-chip regions of the semiconductor substrate passes over a window formed in the base plate;   detecting light reflected from the non-chip regions; and   determining a film thickness of the outermost layer of the semiconductor substrate.